PT-2026-20868 · Microsoft · Inmemoryvectorstore+1

Amiteliahu + 2 · Published 2026-02-19 · Updated 2026-06-07 · CVE-2026-26030

Positive Technologies (AI Summary)

CVSS v3.1

9.9

Critical

Base vector

AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Semantic Kernel Python SDK versions prior to 1.39.4

Description A remote code execution issue exists within the InMemoryVectorStore filter functionality. The flaw occurs in the InMemoryCollection. parse and validate filter function, where a specially crafted filter str can access Python object internals, such as globals, allowing an attacker to escalate a prompt injection into arbitrary code execution.

Recommendations Update Semantic Kernel Python SDK to version 1.39.4 or later. As a temporary workaround, avoid using InMemoryVectorStore for production scenarios.

Exploit

Fix

RCE

Code Injection

Weakness Enumeration

CWE-94

Related Identifiers

CVE-2026-26030

GHSA-XJW9-4GW8-4RQX

PYSEC-2026-163

Affected Products

Inmemoryvectorstore

Semantic-Kernel

References · 50

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26030.json · Exploit
• https://github.com/microsoft/semantic-kernel/pull/13505 · Patch
• https://github.com/microsoft/semantic-kernel/security/advisories/GHSA-xjw9-4gw8-4rqx · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-26030 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-26030 · Security Note
• https://osv.dev/vulnerability/GHSA-xjw9-4gw8-4rqx · Vendor Advisory
• https://osv.dev/vulnerability/PYSEC-2026-163 · Vendor Advisory
• https://github.com/microsoft/semantic-kernel/releases/tag/python-1.39.4 · Note
• https://github.com/microsoft/semantic-kernel · Note
• https://twitter.com/pulsepatchio/status/2024859231971938360 · Twitter Post
• https://reddit.com/r/learnmachinelearning/comments/1t9ld3l/microsoft_just_confirmed_prompt_injection_rce_two · Reddit Post
• https://twitter.com/elagentecapital/status/2033462194797486201 · Twitter Post
• https://twitter.com/0x_illuminati/status/2055846298939768933 · Twitter Post
• https://twitter.com/jelizor/status/2059581125996023901 · Twitter Post
• https://twitter.com/daridor/status/2029560582270050428 · Twitter Post